I have a garage stereo built off an Alpine deck and two amplifiers with 3 computer power supplies. Currently I turn off the power supplies when not in use to help them last longer. The problem with this is that all my presets and audio configuration gets erased every time. I need help designing something that will act as a backup power source so when I turn off my power supplies it will take over and provide enough power to store the presets. I have tried doing this with a relay and it didn’t switch fast enough I tried using a capacitor with the relay and still couldn’t get it to work.
What would you recommend doing to make this work? Would a simple diode inline with both circuits work so the power supplies don’t feed into each other? Will this hurt the deck? Did I possibly do something wrong with the capacitor to where it wouldn’t work? Also open to other ideas.